Playback device supporting concurrent voice assistants

ABSTRACT

Disclosed herein are example techniques to support multiple voice assistant services. An example implementation may involve a playback device capturing audio from the one or more microphones into one or more buffers as a sound data stream monitoring the sound data stream for a wake word associated with a specific voice assistant service and monitoring the sound data stream for a wake word associated with the media playback system. The playback device generates a second wake-word event corresponding to a voice input when sound data matching the wake word associated with the media playback system in a portion of the sound data stream is detected. The playback device determines that the voice input includes sound data matching one or more playback commands and sends sound data representing the voice input to a voice assistant associated with the media playback system for processing of the second voice input.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 120 to, and is acontinuation of, U.S. non-provisional patent application Ser. No.16/437,437, filed on Jun. 11, 2019, and entitled “Playback DeviceSupporting Concurrent Voice Assistant Services,” which is incorporatedherein by reference in its entirety.

U.S. non-provisional patent application Ser. No. 16/437,437 claimspriority under 35 U.S.C. § 120 to, and is a continuation of, U.S.non-provisional patent application Ser. No. 16/173,797, filed on Oct.29, 2018, and entitled “Voice Control of Playback Device Using VoiceAssistance Service(s),” and issued as U.S. Pat. No. 10,354,658 on Jul.16, 2019, which is incorporated herein by reference in its entirety.

This application claims priority under 35 U.S.C. § 120 to, and is acontinuation of, U.S. non-provisional patent application Ser. No.15/229,868, filed on Aug. 5, 2016 entitled “Multiple Voice Services,”issued as U.S. Pat. No. 10,115,400 on Oct. 30, 2018, which isincorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE

The disclosure is related to consumer goods and, more particularly, tomethods, systems, products, features, services, and other elementsdirected to media playback or some aspect thereof.

BACKGROUND

Options for accessing and listening to digital audio in an out-loudsetting were limited until in 2003, when SONOS, Inc. filed for one ofits first patent applications, entitled “Method for Synchronizing AudioPlayback between Multiple Networked Devices,” and began offering a mediaplayback system for sale in 2005. The Sonos Wireless HiFi System enablespeople to experience music from many sources via one or more networkedplayback devices. Through a software control application installed on asmartphone, tablet, or computer, one can play what he or she wants inany room that has a networked playback device. Additionally, using thecontroller, for example, different songs can be streamed to each roomwith a playback device, rooms can be grouped together for synchronousplayback, or the same song can be heard in all rooms synchronously.

Given the ever growing interest in digital media, there continues to bea need to develop consumer-accessible technologies to further enhancethe listening experience.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, aspects, and advantages of the presently disclosed technologymay be better understood with regard to the following description,appended claims, and accompanying drawings where:

FIG. 1 shows an example media playback system configuration in whichcertain embodiments may be practiced;

FIG. 2 shows a functional block diagram of an example playback device;

FIG. 3 shows a functional block diagram of an example control device;

FIG. 4 shows an example controller interface;

FIG. 5 shows an example plurality of network devices;

FIG. 6 shows a functional block diagram of an example network microphonedevice;

FIG. 7 shows a technique to cause a voice service to process a voiceinput according to example embodiments;

FIG. 8 shows another technique to cause a voice service to process avoice input according to example embodiments; and

FIG. 9 shows a technique to register a voice service according toexample embodiments.

The drawings are for the purpose of illustrating example embodiments,but it is understood that the inventions are not limited to thearrangements and instrumentality shown in the drawings.

DETAILED DESCRIPTION I. Overview

Networked microphone devices (NMDs) may be used to control a householdusing voice control. A NMD may be, for example, a SONOS® playbackdevice, server, or system capable of receiving voice input via amicrophone. Additionally, a NMD may be a device other than a SONOS®playback device, server, or system (e.g., AMAZON® ECHO®, APPLE® IPHONE®)capable of receiving voice inputs via a microphone. U.S. applicationSer. No. 15/098,867 entitled, “Default Playback Device Designation,”which is hereby incorporated by reference, provides examples ofvoice-enabled household architectures. Voice control can be beneficialfor various devices with a “smart” home, such as playback devices,wireless illumination devices, thermostats, door locks, home automation,as well as other examples.

In some implementations, voice inputs detected by a NMD are sent to avoice service for processing. A NMD, such as a playback device, mayoperate as a microphone/speaker interface to the voice service. Voiceinputs are detected by a microphone of the NMD and then transmitted to aparticular voice service for processing. The voice service may thenreturn a command or other result of the voice input.

A particular voice service may be selected for a media playback system,perhaps during a setup procedure. A user might select the same voiceservice that they use on their smartphone or tablet computer (or otherpersonal electronic device), perhaps because they are familiar with thatvoice service or they wish to have a similar experience using voicecontrol on their playback device as on their smartphone. Where aparticular voice service is configured on a user's smartphone, thesmartphone may transmit configuration information (e.g., usercredentials) for the voice service to the NMD to facilitate automaticconfiguration of that voice service on the NMD.

In some cases, multiple voice services may be configured for a NMD, or asystem of NMDS (e.g., a media playback system of playback devices). Oneor more services might be configured during a set-up procedure.Additional voice services may be configured for the system later on. Assuch, a NMD as described herein may act as an interface with multiplevoice services, perhaps alleviating a need to have a NMD from each ofthe voice services to interact with the respective voice services. Yetfurther, the NMD may operate in concert with service-specific NMDspresent in a household to process a given voice command.

Where two or more voice services are configured for a NMD, a particularvoice service can be invoked by utterance of a wake-work correspondingto the particular voice service. For instance, in querying AMAZON®, auser might speak the wake-word “Alexa” followed by a voice input. Otherexamples include “Ok, Google” for querying GOOGLE® and “Hey, Siri” forquerying APPLE®.

Alternatively, if no wake-word is used with a given voice input, thenthe NMD may identify a voice service to process that voice input. Insome cases, the NMD might identify a default voice service.Alternatively, the NMD may identify a particular voice service based oncontext. For instance, the NMD may use a recently-queried voice servicebased on the assumption that the user would like to use the same voiceservice again. Other examples are also possible.

As noted above, in some cases, a generic wake-word may be used toindicate a voice input to a NMD. In some cases, this may be amanufacturer-specific wake-word rather than a wake-word tied to anyparticular voice service (e.g., “Hey, Sonos” where the NMD is a SONOS®playback device). Given such a wake-word, the NMD may identify aparticular voice service to process the request. For instance, if thevoice input following the wake-word is related to a particular type ofcommand (e.g., music playback), then the voice input may be sent to aparticular voice service associated with that type of command (e.g. astreaming music service having voice command capabilities).

In some cases, the NMD may transmit the voice input to multiple voiceservices, which may result in respective results from the queried voiceservices. The NMD may evaluate the results and respond with the “best”result (e.g., the result best matching the intended action). Forinstance, if the voice input was “Hey, Sonos, play Taylor Swift,” afirst voice service might respond with “Taylor Swift” search resultswhile a second voice service responds with identifiers of audio tracksby artist Taylor Swift. In that case, the NMD may use the identifiers ofTaylor Swift audio tracks from the second voice service to play backTaylor Swift music in accordance with the voice input.

As noted above, example techniques relate to voice services. An exampleimplementation may include a NMD receiving, via a microphone, voice dataindicating a voice input. The NMD may identify, from among multiplevoice services registered to a media playback system, a voice service toprocess the voice input and cause the identified voice service toprocess the voice input.

Another example implementation may include a NMD receiving input dataindicating a command to register one or more voice services with a mediaplayback system. The NMD may detect voice services that are registeredon the NMD. The NMD may cause the voice services that are registered onthe NMD to be registered on the media playback system.

A third example implementation may include a NMD receiving, via amicrophone, voice data indicating a voice input. The NMD may determinethat a portion of the received voice data represents a generic wake-wordnot corresponding to a specific voice service. The NMD may causemultiple voice services to process the voice input. The NMD may outputresults from a given one of the multiple voice services.

Each of the these example implementations may be embodied as a method, adevice configured to carry out the implementation, a system of devicesconfigured to carry out the implementation, or a non-transitorycomputer-readable medium containing instructions that are executable byone or more processors to carry out the implementation, among otherexamples. It will be understood by one of ordinary skill in the art thatthis disclosure includes numerous other embodiments, includingcombinations of the example features described herein. Further, anyexample operation described as being performed by a given device toillustrate a technique may be performed by any suitable devices,including the devices described herein. Yet further, any device maycause another device to perform any of the operations described herein.

While some examples described herein may refer to functions performed bygiven actors such as “users” and/or other entities, it should beunderstood that this description is for purposes of explanation only.The claims should not be interpreted to require action by any suchexample actor unless explicitly required by the language of the claimsthemselves.

II. Example Operating Environment

FIG. 1 shows an example configuration of a media playback system 100 inwhich one or more embodiments disclosed herein may be practiced orimplemented. The media playback system 100 as shown is associated withan example home environment having several rooms and spaces, such as forexample, a master bedroom, an office, a dining room, and a living room.As shown in the example of FIG. 1, the media playback system 100includes playback devices 102, 104, 106, 108, 110, 112, 114, 116, 118,120, 122, and 124, control devices 126 and 128, and a wired or wirelessnetwork router 130.

Further discussions relating to the different components of the examplemedia playback system 100 and how the different components may interactto provide a user with a media experience may be found in the followingsections. While discussions herein may generally refer to the examplemedia playback system 100, technologies described herein are not limitedto applications within, among other things, the home environment asshown in FIG. 1. For instance, the technologies described herein may beuseful in environments where multi-zone audio may be desired, such as,for example, a commercial setting like a restaurant, mall or airport, avehicle like a sports utility vehicle (SUV), bus or car, a ship or boat,an airplane, and so on.

a. Example Playback Devices

FIG. 2 shows a functional block diagram of an example playback device200 that may be configured to be one or more of the playback devices102-124 of the media playback system 100 of FIG. 1. The playback device200 may include a processor 202, software components 204, memory 206,audio processing components 208, audio amplifier(s) 210, speaker(s) 212,a network interface 214 including wireless interface(s) 216 and wiredinterface(s) 218, and microphone(s) 220. In one case, the playbackdevice 200 may not include the speaker(s) 212, but rather a speakerinterface for connecting the playback device 200 to external speakers.In another case, the playback device 200 may include neither thespeaker(s) 212 nor the audio amplifier(s) 210, but rather an audiointerface for connecting the playback device 200 to an external audioamplifier or audio-visual receiver.

In one example, the processor 202 may be a clock-driven computingcomponent configured to process input data according to instructionsstored in the memory 206. The memory 206 may be a tangiblecomputer-readable medium configured to store instructions executable bythe processor 202. For instance, the memory 206 may be data storage thatcan be loaded with one or more of the software components 204 executableby the processor 202 to achieve certain functions. In one example, thefunctions may involve the playback device 200 retrieving audio data froman audio source or another playback device. In another example, thefunctions may involve the playback device 200 sending audio data toanother device or playback device on a network. In yet another example,the functions may involve pairing of the playback device 200 with one ormore playback devices to create a multi-channel audio environment.

Certain functions may involve the playback device 200 synchronizingplayback of audio content with one or more other playback devices.During synchronous playback, a listener will preferably not be able toperceive time-delay differences between playback of the audio content bythe playback device 200 and the one or more other playback devices. U.S.Pat. No. 8,234,395 entitled, “System and method for synchronizingoperations among a plurality of independently clocked digital dataprocessing devices,” which is hereby incorporated by reference, providesin more detail some examples for audio playback synchronization amongplayback devices.

The memory 206 may further be configured to store data associated withthe playback device 200, such as one or more zones and/or zone groupsthe playback device 200 is a part of, audio sources accessible by theplayback device 200, or a playback queue that the playback device 200(or some other playback device) may be associated with. The data may bestored as one or more state variables that are periodically updated andused to describe the state of the playback device 200. The memory 206may also include the data associated with the state of the other devicesof the media system, and shared from time to time among the devices sothat one or more of the devices have the most recent data associatedwith the system. Other embodiments are also possible.

The audio processing components 208 may include one or moredigital-to-analog converters (DAC), an audio preprocessing component, anaudio enhancement component or a digital signal processor (DSP), and soon. In one embodiment, one or more of the audio processing components208 may be a subcomponent of the processor 202. In one example, audiocontent may be processed and/or intentionally altered by the audioprocessing components 208 to produce audio signals. The produced audiosignals may then be provided to the audio amplifier(s) 210 foramplification and playback through speaker(s) 212. Particularly, theaudio amplifier(s) 210 may include devices configured to amplify audiosignals to a level for driving one or more of the speakers 212. Thespeaker(s) 212 may include an individual transducer (e.g., a “driver”)or a complete speaker system involving an enclosure with one or moredrivers. A particular driver of the speaker(s) 212 may include, forexample, a subwoofer (e.g., for low frequencies), a mid-range driver(e.g., for middle frequencies), and/or a tweeter (e.g., for highfrequencies). In some cases, each transducer in the one or more speakers212 may be driven by an individual corresponding audio amplifier of theaudio amplifier(s) 210. In addition to producing analog signals forplayback by the playback device 200, the audio processing components 208may be configured to process audio content to be sent to one or moreother playback devices for playback.

Audio content to be processed and/or played back by the playback device200 may be received from an external source, such as via an audioline-in input connection (e.g., an auto-detecting 3.5 mm audio line-inconnection) or the network interface 214.

The network interface 214 may be configured to facilitate a data flowbetween the playback device 200 and one or more other devices on a datanetwork. As such, the playback device 200 may be configured to receiveaudio content over the data network from one or more other playbackdevices in communication with the playback device 200, network deviceswithin a local area network, or audio content sources over a wide areanetwork such as the Internet. In one example, the audio content andother signals transmitted and received by the playback device 200 may betransmitted in the form of digital packet data containing an InternetProtocol (IP)-based source address and IP-based destination addresses.In such a case, the network interface 214 may be configured to parse thedigital packet data such that the data destined for the playback device200 is properly received and processed by the playback device 200.

As shown, the network interface 214 may include wireless interface(s)216 and wired interface(s) 218. The wireless interface(s) 216 mayprovide network interface functions for the playback device 200 towirelessly communicate with other devices (e.g., other playbackdevice(s), speaker(s), receiver(s), network device(s), control device(s)within a data network the playback device 200 is associated with) inaccordance with a communication protocol (e.g., any wireless standardincluding IEEE 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.15, 4Gmobile communication standard, and so on). The wired interface(s) 218may provide network interface functions for the playback device 200 tocommunicate over a wired connection with other devices in accordancewith a communication protocol (e.g., IEEE 802.3). While the networkinterface 214 shown in FIG. 2 includes both wireless interface(s) 216and wired interface(s) 218, the network interface 214 may in someembodiments include only wireless interface(s) or only wiredinterface(s).

The microphone(s) 220 may be arranged to detect sound in the environmentof the playback device 200. For instance, the microphone(s) may bemounted on an exterior wall of a housing of the playback device. Themicrophone(s) may be any type of microphone now known or later developedsuch as a condenser microphone, electret condenser microphone, or adynamic microphone. The microphone(s) may be sensitive to a portion ofthe frequency range of the speaker(s) 220. One or more of the speaker(s)220 may operate in reverse as the microphone(s) 220. In some aspects,the playback device 200 might not include the microphone(s) 220.

In one example, the playback device 200 and one other playback devicemay be paired to play two separate audio components of audio content.For instance, playback device 200 may be configured to play a leftchannel audio component, while the other playback device may beconfigured to play a right channel audio component, thereby producing orenhancing a stereo effect of the audio content. The paired playbackdevices (also referred to as “bonded playback devices”) may further playaudio content in synchrony with other playback devices.

In another example, the playback device 200 may be sonicallyconsolidated with one or more other playback devices to form a single,consolidated playback device. A consolidated playback device may beconfigured to process and reproduce sound differently than anunconsolidated playback device or playback devices that are paired,because a consolidated playback device may have additional speakerdrivers through which audio content may be rendered. For instance, ifthe playback device 200 is a playback device designed to render lowfrequency range audio content (i.e. a subwoofer), the playback device200 may be consolidated with a playback device designed to render fullfrequency range audio content. In such a case, the full frequency rangeplayback device, when consolidated with the low frequency playbackdevice 200, may be configured to render only the mid and high frequencycomponents of audio content, while the low frequency range playbackdevice 200 renders the low frequency component of the audio content. Theconsolidated playback device may further be paired with a singleplayback device or yet another consolidated playback device.

By way of illustration, SONOS, Inc. presently offers (or has offered)for sale certain playback devices including a “PLAY:1,” “PLAY:3,”“PLAY:5,” “PLAYBAR,” “CONNECT:AMP,” “CONNECT,” and “SUB.” Any otherpast, present, and/or future playback devices may additionally oralternatively be used to implement the playback devices of exampleembodiments disclosed herein. Additionally, it is understood that aplayback device is not limited to the example illustrated in FIG. 2 orto the SONOS product offerings. For example, a playback device mayinclude a wired or wireless headphone. In another example, a playbackdevice may include or interact with a docking station for personalmobile media playback devices. In yet another example, a playback devicemay be integral to another device or component such as a television, alighting fixture, or some other device for indoor or outdoor use.

b. Example Playback Zone Configurations

Referring back to the media playback system 100 of FIG. 1, theenvironment may have one or more playback zones, each with one or moreplayback devices. The media playback system 100 may be established withone or more playback zones, after which one or more zones may be added,or removed to arrive at the example configuration shown in FIG. 1. Eachzone may be given a name according to a different room or space such asan office, bathroom, master bedroom, bedroom, kitchen, dining room,living room, and/or balcony. In one case, a single playback zone mayinclude multiple rooms or spaces. In another case, a single room orspace may include multiple playback zones.

As shown in FIG. 1, the balcony, dining room, kitchen, bathroom, office,and bedroom zones each have one playback device, while the living roomand master bedroom zones each have multiple playback devices. In theliving room zone, playback devices 104, 106, 108, and 110 may beconfigured to play audio content in synchrony as individual playbackdevices, as one or more bonded playback devices, as one or moreconsolidated playback devices, or any combination thereof. Similarly, inthe case of the master bedroom, playback devices 122 and 124 may beconfigured to play audio content in synchrony as individual playbackdevices, as a bonded playback device, or as a consolidated playbackdevice.

In one example, one or more playback zones in the environment of FIG. 1may each be playing different audio content. For instance, the user maybe grilling in the balcony zone and listening to hip hop music beingplayed by the playback device 102 while another user may be preparingfood in the kitchen zone and listening to classical music being playedby the playback device 114. In another example, a playback zone may playthe same audio content in synchrony with another playback zone. Forinstance, the user may be in the office zone where the playback device118 is playing the same rock music that is being playing by playbackdevice 102 in the balcony zone. In such a case, playback devices 102 and118 may be playing the rock music in synchrony such that the user mayseamlessly (or at least substantially seamlessly) enjoy the audiocontent that is being played out-loud while moving between differentplayback zones. Synchronization among playback zones may be achieved ina manner similar to that of synchronization among playback devices, asdescribed in previously referenced U.S. Pat. No. 8,234,395.

As suggested above, the zone configurations of the media playback system100 may be dynamically modified, and in some embodiments, the mediaplayback system 100 supports numerous configurations. For instance, if auser physically moves one or more playback devices to or from a zone,the media playback system 100 may be reconfigured to accommodate thechange(s). For instance, if the user physically moves the playbackdevice 102 from the balcony zone to the office zone, the office zone maynow include both the playback device 118 and the playback device 102.The playback device 102 may be paired or grouped with the office zoneand/or renamed if so desired via a control device such as the controldevices 126 and 128. On the other hand, if the one or more playbackdevices are moved to a particular area in the home environment that isnot already a playback zone, a new playback zone may be created for theparticular area.

Further, different playback zones of the media playback system 100 maybe dynamically combined into zone groups or split up into individualplayback zones. For instance, the dining room zone and the kitchen zone114 may be combined into a zone group for a dinner party such thatplayback devices 112 and 114 may render audio content in synchrony. Onthe other hand, the living room zone may be split into a television zoneincluding playback device 104, and a listening zone including playbackdevices 106, 108, and 110, if the user wishes to listen to music in theliving room space while another user wishes to watch television.

c. Example Control Devices

FIG. 3 shows a functional block diagram of an example control device 300that may be configured to be one or both of the control devices 126 and128 of the media playback system 100. As shown, the control device 300may include a processor 302, memory 304, a network interface 306, a userinterface 308, microphone(s) 310, and software components 312. In oneexample, the control device 300 may be a dedicated controller for themedia playback system 100. In another example, the control device 300may be a network device on which media playback system controllerapplication software may be installed, such as for example, an iPhone™,iPad™ or any other smart phone, tablet or network device (e.g., anetworked computer such as a PC or Mac™).

The processor 302 may be configured to perform functions relevant tofacilitating user access, control, and configuration of the mediaplayback system 100. The memory 304 may be data storage that can beloaded with one or more of the software components executable by theprocessor 302 to perform those functions. The memory 304 may also beconfigured to store the media playback system controller applicationsoftware and other data associated with the media playback system 100and the user.

In one example, the network interface 306 may be based on an industrystandard (e.g., infrared, radio, wired standards including IEEE 802.3,wireless standards including IEEE 802.11a, 802.11b, 802.11g, 802.11n,802.11ac, 802.15, 4G mobile communication standard, and so on). Thenetwork interface 306 may provide a means for the control device 300 tocommunicate with other devices in the media playback system 100. In oneexample, data and information (e.g., such as a state variable) may becommunicated between control device 300 and other devices via thenetwork interface 306. For instance, playback zone and zone groupconfigurations in the media playback system 100 may be received by thecontrol device 300 from a playback device or another network device, ortransmitted by the control device 300 to another playback device ornetwork device via the network interface 306. In some cases, the othernetwork device may be another control device.

Playback device control commands such as volume control and audioplayback control may also be communicated from the control device 300 toa playback device via the network interface 306. As suggested above,changes to configurations of the media playback system 100 may also beperformed by a user using the control device 300. The configurationchanges may include adding/removing one or more playback devices to/froma zone, adding/removing one or more zones to/from a zone group, forminga bonded or consolidated player, separating one or more playback devicesfrom a bonded or consolidated player, among others. Accordingly, thecontrol device 300 may sometimes be referred to as a controller, whetherthe control device 300 is a dedicated controller or a network device onwhich media playback system controller application software isinstalled.

Control device 300 may include microphone(s) 310. Microphone(s) 310 maybe arranged to detect sound in the environment of the control device300. Microphone(s) 310 may be any type of microphone now known or laterdeveloped such as a condenser microphone, electret condenser microphone,or a dynamic microphone. The microphone(s) may be sensitive to a portionof a frequency range. Two or more microphones 310 may be arranged tocapture location information of an audio source (e.g., voice, audiblesound) and/or to assist in filtering background noise.

The user interface 308 of the control device 300 may be configured tofacilitate user access and control of the media playback system 100, byproviding a controller interface such as the controller interface 400shown in FIG. 4. The controller interface 400 includes a playbackcontrol region 410, a playback zone region 420, a playback status region430, a playback queue region 440, and an audio content sources region450. The user interface 400 as shown is just one example of a userinterface that may be provided on a network device such as the controldevice 300 of FIG. 3 (and/or the control devices 126 and 128 of FIG. 1)and accessed by users to control a media playback system such as themedia playback system 100. Other user interfaces of varying formats,styles, and interactive sequences may alternatively be implemented onone or more network devices to provide comparable control access to amedia playback system.

The playback control region 410 may include selectable (e.g., by way oftouch or by using a cursor) icons to cause playback devices in aselected playback zone or zone group to play or pause, fast forward,rewind, skip to next, skip to previous, enter/exit shuffle mode,enter/exit repeat mode, enter/exit cross fade mode. The playback controlregion 410 may also include selectable icons to modify equalizationsettings, and playback volume, among other possibilities.

The playback zone region 420 may include representations of playbackzones within the media playback system 100. In some embodiments, thegraphical representations of playback zones may be selectable to bringup additional selectable icons to manage or configure the playback zonesin the media playback system, such as a creation of bonded zones,creation of zone groups, separation of zone groups, and renaming of zonegroups, among other possibilities.

For example, as shown, a “group” icon may be provided within each of thegraphical representations of playback zones. The “group” icon providedwithin a graphical representation of a particular zone may be selectableto bring up options to select one or more other zones in the mediaplayback system to be grouped with the particular zone. Once grouped,playback devices in the zones that have been grouped with the particularzone will be configured to play audio content in synchrony with theplayback device(s) in the particular zone. Analogously, a “group” iconmay be provided within a graphical representation of a zone group. Inthis case, the “group” icon may be selectable to bring up options todeselect one or more zones in the zone group to be removed from the zonegroup. Other interactions and implementations for grouping andungrouping zones via a user interface such as the user interface 400 arealso possible. The representations of playback zones in the playbackzone region 420 may be dynamically updated as playback zone or zonegroup configurations are modified.

The playback status region 430 may include graphical representations ofaudio content that is presently being played, previously played, orscheduled to play next in the selected playback zone or zone group. Theselected playback zone or zone group may be visually distinguished onthe user interface, such as within the playback zone region 420 and/orthe playback status region 430. The graphical representations mayinclude track title, artist name, album name, album year, track length,and other relevant information that may be useful for the user to knowwhen controlling the media playback system via the user interface 400.

The playback queue region 440 may include graphical representations ofaudio content in a playback queue associated with the selected playbackzone or zone group. In some embodiments, each playback zone or zonegroup may be associated with a playback queue containing informationcorresponding to zero or more audio items for playback by the playbackzone or zone group. For instance, each audio item in the playback queuemay comprise a uniform resource identifier (URI), a uniform resourcelocator (URL) or some other identifier that may be used by a playbackdevice in the playback zone or zone group to find and/or retrieve theaudio item from a local audio content source or a networked audiocontent source, possibly for playback by the playback device.

In one example, a playlist may be added to a playback queue, in whichcase information corresponding to each audio item in the playlist may beadded to the playback queue. In another example, audio items in aplayback queue may be saved as a playlist. In a further example, aplayback queue may be empty, or populated but “not in use” when theplayback zone or zone group is playing continuously streaming audiocontent, such as Internet radio that may continue to play untilotherwise stopped, rather than discrete audio items that have playbackdurations. In an alternative embodiment, a playback queue can includeInternet radio and/or other streaming audio content items and be “inuse” when the playback zone or zone group is playing those items. Otherexamples are also possible.

When playback zones or zone groups are “grouped” or “ungrouped,”playback queues associated with the affected playback zones or zonegroups may be cleared or re-associated. For example, if a first playbackzone including a first playback queue is grouped with a second playbackzone including a second playback queue, the established zone group mayhave an associated playback queue that is initially empty, that containsaudio items from the first playback queue (such as if the secondplayback zone was added to the first playback zone), that contains audioitems from the second playback queue (such as if the first playback zonewas added to the second playback zone), or a combination of audio itemsfrom both the first and second playback queues. Subsequently, if theestablished zone group is ungrouped, the resulting first playback zonemay be re-associated with the previous first playback queue, or beassociated with a new playback queue that is empty or contains audioitems from the playback queue associated with the established zone groupbefore the established zone group was ungrouped. Similarly, theresulting second playback zone may be re-associated with the previoussecond playback queue, or be associated with a new playback queue thatis empty, or contains audio items from the playback queue associatedwith the established zone group before the established zone group wasungrouped. Other examples are also possible.

Referring back to the user interface 400 of FIG. 4, the graphicalrepresentations of audio content in the playback queue region 440 mayinclude track titles, artist names, track lengths, and other relevantinformation associated with the audio content in the playback queue. Inone example, graphical representations of audio content may beselectable to bring up additional selectable icons to manage and/ormanipulate the playback queue and/or audio content represented in theplayback queue. For instance, a represented audio content may be removedfrom the playback queue, moved to a different position within theplayback queue, or selected to be played immediately, or after anycurrently playing audio content, among other possibilities. A playbackqueue associated with a playback zone or zone group may be stored in amemory on one or more playback devices in the playback zone or zonegroup, on a playback device that is not in the playback zone or zonegroup, and/or some other designated device.

The audio content sources region 450 may include graphicalrepresentations of selectable audio content sources from which audiocontent may be retrieved and played by the selected playback zone orzone group. Discussions pertaining to audio content sources may be foundin the following section.

d. Example Audio Content Sources

As indicated previously, one or more playback devices in a zone or zonegroup may be configured to retrieve for playback audio content (e.g.according to a corresponding URI or URL for the audio content) from avariety of available audio content sources. In one example, audiocontent may be retrieved by a playback device directly from acorresponding audio content source (e.g., a line-in connection). Inanother example, audio content may be provided to a playback device overa network via one or more other playback devices or network devices.

Example audio content sources may include a memory of one or moreplayback devices in a media playback system such as the media playbacksystem 100 of FIG. 1, local music libraries on one or more networkdevices (such as a control device, a network-enabled personal computer,or a networked-attached storage (NAS), for example), streaming audioservices providing audio content via the Internet (e.g., the cloud), oraudio sources connected to the media playback system via a line-in inputconnection on a playback device or network devise, among otherpossibilities.

In some embodiments, audio content sources may be regularly added orremoved from a media playback system such as the media playback system100 of FIG. 1. In one example, an indexing of audio items may beperformed whenever one or more audio content sources are added, removedor updated. Indexing of audio items may involve scanning foridentifiable audio items in all folders/directory shared over a networkaccessible by playback devices in the media playback system, andgenerating or updating an audio content database containing metadata(e.g., title, artist, album, track length, among others) and otherassociated information, such as a URI or URL for each identifiable audioitem found. Other examples for managing and maintaining audio contentsources may also be possible.

The above discussions relating to playback devices, controller devices,playback zone configurations, and media content sources provide onlysome examples of operating environments within which functions andmethods described below may be implemented. Other operating environmentsand configurations of media playback systems, playback devices, andnetwork devices not explicitly described herein may also be applicableand suitable for implementation of the functions and methods.

e. Example Plurality of Networked Devices

FIG. 5 shows an example plurality of devices 500 that may be configuredto provide an audio playback experience based on voice control. Onehaving ordinary skill in the art will appreciate that the devices shownin FIG. 5 are for illustrative purposes only, and variations includingdifferent and/or additional devices may be possible. As shown, theplurality of devices 500 includes computing devices 504, 506, and 508;network microphone devices (NMDs) 512, 514, and 516; playback devices(PBDs) 532, 534, 536, and 538; and a controller device (CR) 522.

Each of the plurality of devices 500 may be network-capable devices thatcan establish communication with one or more other devices in theplurality of devices according to one or more network protocols, such asNFC, Bluetooth, Ethernet, and IEEE 802.11, among other examples, overone or more types of networks, such as wide area networks (WAN), localarea networks (LAN), and personal area networks (PAN), among otherpossibilities.

As shown, the computing devices 504, 506, and 508 may be part of a cloudnetwork 502. The cloud network 502 may include additional computingdevices. In one example, the computing devices 504, 506, and 508 may bedifferent servers. In another example, two or more of the computingdevices 504, 506, and 508 may be modules of a single server.Analogously, each of the computing device 504, 506, and 508 may includeone or more modules or servers. For ease of illustration purposesherein, each of the computing devices 504, 506, and 508 may beconfigured to perform particular functions within the cloud network 502.For instance, computing device 508 may be a source of audio content fora streaming music service.

As shown, the computing device 504 may be configured to interface withNMDs 512, 514, and 516 via communication path 542. NMDs 512, 514, and516 may be components of one or more “Smart Home” systems. In one case,NMDs 512, 514, and 516 may be physically distributed throughout ahousehold, similar to the distribution of devices shown in FIG. 1. Inanother case, two or more of the NMDs 512, 514, and 516 may bephysically positioned within relative close proximity of one another.Communication path 542 may comprise one or more types of networks, suchas a WAN including the Internet, LAN, and/or PAN, among otherpossibilities.

In one example, one or more of the NMDs 512, 514, and 516 may be devicesconfigured primarily for audio detection. In another example, one ormore of the NMDs 512, 514, and 516 may be components of devices havingvarious primary utilities. For instance, as discussed above inconnection to FIGS. 2 and 3, one or more of NMDs 512, 514, and 516 maybe the microphone(s) 220 of playback device 200 or the microphone(s) 310of network device 300. Further, in some cases, one or more of NMDs 512,514, and 516 may be the playback device 200 or network device 300. In anexample, one or more of NMDs 512, 514, and/or 516 may include multiplemicrophones arranged in a microphone array.

As shown, the computing device 506 may be configured to interface withCR 522 and PBDs 532, 534, 536, and 538 via communication path 544. Inone example, CR 522 may be a network device such as the network device200 of FIG. 2. Accordingly, CR 522 may be configured to provide thecontroller interface 400 of FIG. 4. Similarly, PBDs 532, 534, 536, and538 may be playback devices such as the playback device 300 of FIG. 3.As such, PBDs 532, 534, 536, and 538 may be physically distributedthroughout a household as shown in FIG. 1. For illustration purposes,PBDs 536 and 538 may be part of a bonded zone 530, while PBDs 532 and534 may be part of their own respective zones. As described above, thePBDs 532, 534, 536, and 538 may be dynamically bonded, grouped,unbonded, and ungrouped. Communication path 544 may comprise one or moretypes of networks, such as a WAN including the Internet, LAN, and/orPAN, among other possibilities.

In one example, as with NMDs 512, 514, and 516, CR 522 and PBDs 532,534, 536, and 538 may also be components of one or more “Smart Home”systems. In one case, PBDs 532, 534, 536, and 538 may be distributedthroughout the same household as the NMDs 512, 514, and 516. Further, assuggested above, one or more of PBDs 532, 534, 536, and 538 may be oneor more of NMDs 512, 514, and 516.

The NMDs 512, 514, and 516 may be part of a local area network, and thecommunication path 542 may include an access point that links the localarea network of the NMDs 512, 514, and 516 to the computing device 504over a WAN (communication path not shown). Likewise, each of the NMDs512, 514, and 516 may communicate with each other via such an accesspoint.

Similarly, CR 522 and PBDs 532, 534, 536, and 538 may be part of a localarea network and/or a local playback network as discussed in previoussections, and the communication path 544 may include an access pointthat links the local area network and/or local playback network of CR522 and PBDs 532, 534, 536, and 538 to the computing device 506 over aWAN. As such, each of the CR 522 and PBDs 532, 534, 536, and 538 mayalso communicate with each over such an access point.

In one example, a single access point may include communication paths542 and 544. In an example, each of the NMDs 512, 514, and 516, CR 522,and PBDs 532, 534, 536, and 538 may access the cloud network 502 via thesame access point for a household.

As shown in FIG. 5, each of the NMDs 512, 514, and 516, CR 522, and PBDs532, 534, 536, and 538 may also directly communicate with one or more ofthe other devices via communication means 546. Communication means 546as described herein may involve one or more forms of communicationbetween the devices, according to one or more network protocols, overone or more types of networks, and/or may involve communication via oneor more other network devices. For instance, communication means 546 mayinclude one or more of for example, Bluetooth™ (IEEE 802.15), NFC,Wireless direct, and/or Proprietary wireless, among other possibilities.

In one example, CR 522 may communicate with NMD 512 over Bluetooth™, andcommunicate with PBD 534 over another local area network. In anotherexample, NMD 514 may communicate with CR 522 over another local areanetwork, and communicate with PBD 536 over Bluetooth. In a furtherexample, each of the PBDs 532, 534, 536, and 538 may communicate witheach other according to a spanning tree protocol over a local playbacknetwork, while each communicating with CR 522 over a local area network,different from the local playback network. Other examples are alsopossible.

In some cases, communication means between the NMDs 512, 514, and 516,CR 522, and PBDs 532, 534, 536, and 538 may change depending on types ofcommunication between the devices, network conditions, and/or latencydemands. For instance, communication means 546 may be used when NMD 516is first introduced to the household with the PBDs 532, 534, 536, and538. In one case, the NMD 516 may transmit identification informationcorresponding to the NMD 516 to PBD 538 via NFC, and PBD 538 may inresponse, transmit local area network information to NMD 516 via NFC (orsome other form of communication). However, once NMD 516 has beenconfigured within the household, communication means between NMD 516 andPBD 538 may change. For instance, NMD 516 may subsequently communicatewith PBD 538 via communication path 542, the cloud network 502, andcommunication path 544. In another example, the NMDs and PBDs may nevercommunicate via local communications means 546. In a further example,the NMDs and PBDs may communicate primarily via local communicationsmeans 546. Other examples are also possible.

In an illustrative example, NMDs 512, 514, and 516 may be configured toreceive voice inputs to control PBDs 532, 534, 536, and 538. Theavailable control commands may include any media playback systemcontrols previously discussed, such as playback volume control, playbacktransport controls, music source selection, and grouping, among otherpossibilities. In one instance, NMD 512 may receive a voice input tocontrol one or more of the PBDs 532, 534, 536, and 538. In response toreceiving the voice input, NMD 512 may transmit via communication path542, the voice input to computing device 504 for processing. In oneexample, the computing device 504 may convert the voice input to anequivalent text command, and parse the text command to identify acommand. Computing device 504 may then subsequently transmit the textcommand to the computing device 506. In another example, the computingdevice 504 may convert the voice input to an equivalent text command,and then subsequently transmit the text command to the computing device506. The computing device 506 may then parse the text command toidentify one or more playback commands.

For instance, if the text command is “Play ‘Track 1’ by ‘Artist 1’ from‘Streaming Service 1’ in ‘Zone 1’,” The computing device 506 mayidentify (i) a URL for “Track 1” by “Artist 1” available from “StreamingService 1,” and (ii) at least one playback device in “Zone 1.” In thisexample, the URL for “Track 1” by “Artist 1” from “Streaming Service 1”may be a URL pointing to computing device 508, and “Zone 1” may be thebonded zone 530. As such, upon identifying the URL and one or both ofPBDs 536 and 538, the computing device 506 may transmit viacommunication path 544 to one or both of PBDs 536 and 538, theidentified URL for playback. One or both of PBDs 536 and 538 mayresponsively retrieve audio content from the computing device 508according to the received URL, and begin playing “Track 1” by “Artist 1”from “Streaming Service 1.”

One having ordinary skill in the art will appreciate that the above isjust one illustrative example, and that other implementations are alsopossible. In one case, operations performed by one or more of theplurality of devices 500, as described above, may be performed by one ormore other devices in the plurality of device 500. For instance, theconversion from voice input to the text command may be alternatively,partially, or wholly performed by another device or devices, such as NMD512, computing device 506, PBD 536, and/or PBD 538. Analogously, theidentification of the URL may be alternatively, partially, or whollyperformed by another device or devices, such as NMD 512, computingdevice 504, PBD 536, and/or PBD 538.

f. Example Network Microphone Device

FIG. 6 shows a function block diagram of an example network microphonedevice 600 that may be configured to be one or more of NMDs 512, 514,and 516 of FIG. 5. As shown, the network microphone device 600 includesa processor 602, memory 604, a microphone array 606, a network interface608, a user interface 610, software components 612, and speaker(s) 614.One having ordinary skill in the art will appreciate that other networkmicrophone device configurations and arrangements are also possible. Forinstance, network microphone devices may alternatively exclude thespeaker(s) 614 or have a single microphone instead of microphone array606.

The processor 602 may include one or more processors and/or controllers,which may take the form of a general or special-purpose processor orcontroller. For instance, the processing unit 602 may includemicroprocessors, microcontrollers, application-specific integratedcircuits, digital signal processors, and the like. The memory 604 may bedata storage that can be loaded with one or more of the softwarecomponents executable by the processor 602 to perform those functions.Accordingly, memory 604 may comprise one or more non-transitorycomputer-readable storage mediums, examples of which may includevolatile storage mediums such as random access memory, registers, cache,etc. and non-volatile storage mediums such as read-only memory, ahard-disk drive, a solid-state drive, flash memory, and/or anoptical-storage device, among other possibilities.

The microphone array 606 may be a plurality of microphones arranged todetect sound in the environment of the network microphone device 600.Microphone array 606 may include any type of microphone now known orlater developed such as a condenser microphone, electret condensermicrophone, or a dynamic microphone, among other possibilities. In oneexample, the microphone array may be arranged to detect audio from oneor more directions relative to the network microphone device. Themicrophone array 606 may be sensitive to a portion of a frequency range.In one example, a first subset of the microphone array 606 may besensitive to a first frequency range, while a second subset of themicrophone array may be sensitive to a second frequency range. Themicrophone array 606 may further be arranged to capture locationinformation of an audio source (e.g., voice, audible sound) and/or toassist in filtering background noise. Notably, in some embodiments themicrophone array may consist of only a single microphone, rather than aplurality of microphones.

The network interface 608 may be configured to facilitate wirelessand/or wired communication between various network devices, such as, inreference to FIG. 5, CR 522, PBDs 532-538, computing device 504-508 incloud network 502, and other network microphone devices, among otherpossibilities. As such, network interface 608 may take any suitable formfor carrying out these functions, examples of which may include anEthernet interface, a serial bus interface (e.g., FireWire, USB 2.0,etc.), a chipset and antenna adapted to facilitate wirelesscommunication, and/or any other interface that provides for wired and/orwireless communication. In one example, the network interface 608 may bebased on an industry standard (e.g., infrared, radio, wired standardsincluding IEEE 802.3, wireless standards including IEEE 802.11a,802.11b, 802.11g, 802.11n, 802.11ac, 802.15, 4G mobile communicationstandard, and so on).

The user interface 610 of the network microphone device 600 may beconfigured to facilitate user interactions with the network microphonedevice. In one example, the user interface 608 may include one or moreof physical buttons, graphical interfaces provided on touch sensitivescreen(s) and/or surface(s), among other possibilities, for a user todirectly provide input to the network microphone device 600. The userinterface 610 may further include one or more of lights and thespeaker(s) 614 to provide visual and/or audio feedback to a user. In oneexample, the network microphone device 600 may further be configured toplayback audio content via the speaker(s) 614.

Moving now to several example implementations, implementations 700, 800,and 900 shown in FIGS. 7, 8, and 9, respectively present exampleembodiments of techniques described herein. These example embodimentsthat can be implemented within an operating environment including, forexample, the media playback system 100 of FIG. 1, one or more of theplayback device 200 of FIG. 2, or one or more of the control device 300of FIG. 3, as well as other devices described herein and/or othersuitable devices. Further, operations illustrated by way of example asbeing performed by a media playback system can be performed by anysuitable device, such as a playback device or a control device of amedia playback system. Implementations 700, 800, and 900 may include oneor more operations, functions, or actions as illustrated by one or moreof blocks shown in FIGS. 7, 8, and 9. Although the blocks areillustrated in sequential order, these blocks may also be performed inparallel, and/or in a different order than those described herein. Also,the various blocks may be combined into fewer blocks, divided intoadditional blocks, and/or removed based upon the desired implementation.

In addition, for the implementations disclosed herein, the flowchartsshow functionality and operation of one possible implementation ofpresent embodiments. In this regard, each block may represent a module,a segment, or a portion of program code, which includes one or moreinstructions executable by a processor for implementing specific logicalfunctions or steps in the process. The program code may be stored on anytype of computer readable medium, for example, such as a storage deviceincluding a disk or hard drive. The computer readable medium may includenon-transitory computer readable medium, for example, such ascomputer-readable media that stores data for short periods of time likeregister memory, processor cache, and Random Access Memory (RAM). Thecomputer readable medium may also include non-transitory media, such assecondary or persistent long term storage, like read only memory (ROM),optical or magnetic disks, compact-disc read only memory (CD-ROM), forexample. The computer readable media may also be any other volatile ornon-volatile storage systems. The computer readable medium may beconsidered a computer readable storage medium, for example, or atangible storage device. In addition, for the implementations disclosedherein, each block may represent circuitry that is wired to perform thespecific logical functions in the process.

III. Example Systems and Methods to Invoke Voice Service

As discussed above, in some examples, a computing device may use a voiceservice to process a voice command. Implementation 700 is an exampletechnique to cause a voice service to process a voice input.

a. Receive Voice Data Indicating a Voice Input

At block 702, implementation 700 involves receiving voice dataindicating a voice input. For instance, a NMD, such as NMD 600, mayreceive, via a microphone, voice data indicating a voice input. Asfurther examples, any of playback devices 102, 104, 106, 108, 110, 112,114, 116, 118, 120, 122, and 124 or control devices 126 and 128 of FIG.1 may be a NMD and may receive voice data indicating a voice input. Yetfurther examples NMDs include NMDs 512, 514, and 516, PBDs 532, 534,536, and 538, and CR 522 of FIG. 5.

A NMD may continuously record ambient noise (i.e., listen for voiceinputs) via one or more microphones. The NMD may store the continuousrecording in a ring or circular buffer. In such a buffer, the recordingmay be overwritten (i.e., discarded) unless the recording includes avoice input. The buffer may be stored locally and/or remotely via any ofthe devices or servers described herein. In such cases, receiving voicedata indicating the voice input may involve recording into the buffervoice data that includes the voice input.

A NMD may detect that a voice input has been received by detecting thata portion of the voice data includes a wake-up word or phrase. Forinstance, a voice input might include a wake-word followed by a voicecommand. The wake-word may trigger a time period or window for the NMDto actively listen for a voice input. The time period or window mayexpire after a certain duration of time (e.g., one minute after the NMDreceives an initial voice input). U.S. application Ser. No. 15/131,776entitled, “Action based on User ID,” which is hereby incorporated byreference describes further examples. Several example wake-words incommercial use include “Hey, Siri” (APPLE®), “Ok, Google” (GOOGLE®), and“Alexa” (AMAZON®). Alternatively, a wake-word may be custom (e.g.,user-defined).

To illustrate, referring back to FIG. 1, a user may speak a particularvoice input while in the Master Bedroom zone. Playback device 122(and/or playback device 124), operating as NMDs, may be listening (i.e.,recording via a microphone, perhaps to a buffer) for voice inputs anddetect the user's voice as a voice input. The particular voice input mayinclude a wake-word to facilitate the NMD recognizing the user's voiceas a voice input.

Example voice commands may include commands to modify any of the mediaplayback system controls or playback settings. Playback settings mayinclude, for example, playback volume, playback transport controls,music source selection, and grouping, among other possibilities. Othervoice commands may include operations to adjust television control orplay settings, mobile phone device settings, or illumination devices,among other device operations. As more household devices become “smart”(e.g., by incorporating a network interface), voice commands may be usedto control various household devices.

In some cases, the NMD may receive voice data indicating the voice inputvia a network interface, perhaps from another NMD within a household.The NMD may receive this recording in addition to receiving voice dataindicating the voice input via a microphone (e.g., if the two NMDs areboth within detection range of the voice input).

In such embodiments, the NMD might not continuously record ambientnoise. Rather, in some instances, the NMD may receive a voice input orindication that instructs the NMD to “wake up” and start recording voiceinputs or commands. For example, a first NMD (e.g., playback device 104shown in FIG. 1) may receive a voice input and, in certain situationsdescribed herein, send an indication to one or more second NMDs to startrecording (e.g., playback device 106 and/or 108, among other possibleexamples).

Within examples, the voice recordings from multiple NMDs may be refined,processed, and/or combined into a single voice input before the NMDdevice receives the voice data. By way of example, NMD 512 may receivevoice recordings from one or more other NMDs, such as 514 or 516. Insome embodiments, PBDs 532, 534, 536 and/or 538 may be configured asNMDs, and the NMD 512 may receive voice recordings from one of PBDs 532,534, 536 and/or 538. A NMD (or multiple NMDs) may refine, process,and/or combine the voice recordings into a single voice input and sendthe single voice input to the computing device for further processing.

b. Identify Voice Service(s) to Process the Voice Input

At block 704, implementation 700 involves identifying one or more voiceservices to process the voice input. For instance, a NMD may identify aparticular voice service to process the voice input indicated in thereceived voice data. Alternatively, the NMD may identify multiple voiceservices to process the voice input.

The NMD may identify the particular voice service to process the voiceinput from among available voice services. Voice services may be madeavailable to an NMD using various techniques. Available voice servicesmay include voice services registered with the NMD. Registration of agiven voice service with the NMD may involve providing user credentials(e.g., user name and password) of the voice service to the NMD and/orproviding an identifier of the NMD to the voice service. Suchregistration may configure the NMD to receive voice inputs on behalf ofthe voice service and perhaps configure the voice service to acceptvoice inputs from the NMD for processing. Registration may occur withina set-up procedure.

In some cases, the NMD may be associated with a media playback system.The NMD may operate as part of the media playback system itself (e.g.,as a controller device or playback device) or as another device that isinterconnected with the media playback system, perhaps to facilitatecertain operations of the media playback system (e.g., voice control ofthe playback devices). One or more voice services may be registered witha given media playback system and the NMD may identify a registeredvoice service to process the voice input.

Registration of the media playback system may configure NMDs of themedia playback system (e.g., controller devices, playback devices, orotherwise associated devices) to receive voice inputs on behalf of thevoice service. Further, registration may configure the voice service toaccept voice inputs from these devices for processing. Registration of avoice service with a media playback system may occur within a set-upprocedure. Example set-up procedures include procedures to set-up aplayback device (or multiple playback devices) and/or a controllerdevice into a new media playback system. Other example set-up proceduresinclude procedures to modify the media playback system (e.g., to add orremove a device from the system, or to configure a voice service withthe system).

In some cases, a single voice service may be available to the NMD, whichmay simply identification of the voice service to process the voiceinput. Voice inputs received by a NMD may be transmitted directly to thevoice service and responses may be provided by the NMD. In such anembodiment, the NMD operates as a microphone and speaker interface forthe single voice service.

In other cases, multiple voice services may be available to the NMD forprocessing of the voice input. In such cases, the NMD may identify aparticular voice service of the multiple voice services to process thevoice input. For instance, the NMD may identify a particular voiceservice from among multiple voice services registered to a mediaplayback system. As indicated above, the NMD may be part of the mediaplayback system (e.g., as a playback device or controller device) orotherwise associated with the system.

Identification of a particular voice service to process the voice inputmay be based on a wake-word or phrase in the voice input. For instance,after receiving voice data indicating a voice input, the NMD maydetermine that a portion of the voice data represents a particularwake-word. Further, the NMD may determine that the particular wake-wordcorresponds to a specific voice service. In other words, the NMD maydetermine that the particular wake-word or phrase is used to invoke aspecific voice service. For instance, the particular wake-word may be“Hey, Siri” to invoke APPLE®'s voice service, “Ok, Google” to invokeGOOGLE®'s voice service, “Alexa” to invoke AMAZON®'s voice service, or“Hey, Cortana” to invoke Microsoft's voice service. Alternatively, acustom wake-word (e.g., user-defined) may be defined to invoke aparticular voice service. Where the NMD determines that particularwake-word in the received voice data corresponds to a specific voiceservice, the NMD may identify that specific voice service as the voiceservice to process the voice input in the voice data.

Determining that the particular wake-word corresponds to a specificvoice service may involve querying one or more voice services with thevoice data (e.g., the portion of the voice data corresponding to thewake-word or phrase). For instance, a voice service may provide anapplication programming interface that the NMD can invoke to determinethat whether the voice data includes the wake-word or phrasecorresponding to that voice service. The NMD may invoke the API bytransmitting a particular query of the voice service to the voiceservice along with data representing the wake-word portion of thereceived voice data. Alternatively, the NMD may invoke the API on theNMD itself. Registration of a voice service with the NMD or with themedia playback system may integrate the API or other architecture of thevoice service with the NMD.

Where multiple voice services are available to the NMD, the NMD mightquery wake-word detection algorithms corresponding to each voice serviceof the multiple voice services. As noted above, querying such detectionalgorithms may involve invoking respective APIs of the multiple voiceservices, either locally on the NMD or remotely using a networkinterface. In response to a query to a wake-word detection algorithm ofa given voice service, the NMD may receive a response indicating whetheror not the voice data in the query included the wake-word correspondingto that voice service. Where a wake-word detection algorithm of aspecific voice service detected that the received voice data representsthe particular wake-word corresponding to the specific voice service,the NMD may select that specific voice service as the voice service toprocess the voice input.

In some cases, the received voice data might not include a recognizablewake-word corresponding to a specific voice service, but nonethelessinclude a voice input. Such a situation may arise, where due to ambientnoise or other factors, a given wake-word might not be clearly detected,such that the wake-word detection algorithm(s) do not recognize thegiven wake-word as corresponding to any specific voice service.Alternatively, a user might not speak a wake-word corresponding to aspecific voice service. For instance, a generic wake-word notcorresponding to a specific voice service might be used to invokeprocessing of the voice input (e.g., “Hey, Sonos”).

In such cases, the NMD may identify a default voice service to processthe voice input based on context. A default voice service may bepre-determined (e.g., configured during a set-up procedure, such as theexample procedures described above). Then, when the NMD determines thatthe received voice data excludes any wake-word corresponding to aspecific voice service (e.g., the NMD does not detect a wake-wordcorresponding to the specific voice service in the voice data), the NMDmay select the default voice service to process the voice input.

As noted above, some example systems may include multiple NMDs, possiblyconfigured into multiple zones (e.g., media playback system 100 of FIG.1 with Living Room, Kitchen, Dining Room, and Bedroom zones, each withrespective playback devices). In such systems, a default voice servicemay be configured on a per NMD or per zone basis. Then, voice inputsdetected by a given NMD or zone may be processed by the default voiceservice for that NMD or zone. In some cases, the NMD may assume that avoice input that was detected by a given NMD or zone is intended to beprocessed by the voice service associated with the zone. However, inother case, a wake-word or phrase may direct the voice input to aparticular NMD or zone (e.g., “Hey, Kitchen” to direct a voice input toa Kitchen zone).

To illustrate, referring to FIG. 1, playback devices 122 and/or 124 mayoperate as NMDs of the Master Bedroom zone. A voice input detected byand/or directed to this zone (e.g., “Hey, Master Bedroom, what's theweather today?”) may be processed by the default voice service for theMaster Bedroom zone. For instance, if the default voice service for theMaster Bedroom zone is “AMAZON® Alexa®”, then at least one of the NMDsof the Master Bedroom zone will query Alexa for the weather. Where avoice input includes a wake-word or phrase corresponding to a specificvoice service, the wake-word or phrase may override the default voiceservice (if the specific voice service is different from the defaultvoice service) and cause the NMD to identify the specific voice serviceto process the voice input.

In some implementations, the NMD may identify the voice service based onthe identity of the user providing the voice input. Human voices canvary by pitch, timbre, and other qualities, which may providecharacteristics by which to identify a particular user by their voice.In some cases, users in a household may train a NMD to recognize theirrespective voices.

Each user in a household may have their own preferred voice service. Forinstance, a first user and a second user in a household may configurethe NMD to use a first and second voice service, respectively (e.g.,SIRI® and CORTANA®). If the NMD recognizes the first user's voice in thevoice input, then the NMD may identify the first voice service toprocess the voice command. However, if the NMD recognizes the seconduser's voice in the voice input, then the NMD may instead identify thesecond voice service to process the voice command.

Alternatively, the NMD may identify a particular voice service toprocess the voice input based on context. For instance, the NMD mayidentify a particular voice service based on the type of command. An NMD(e.g., a NMD that is associated with a media playback system) mayrecognize certain commands (e.g., play, pause, skip forward, etc.) asbeing a particular type of command (e.g., media playback commands). Insuch cases, when the NMD determines that the voice input includes aparticular type of command (e.g., a media playback command), the NMD mayidentify, as the voice service to process that voice input, a particularvoice service configured to process that type of command. To furtherillustrate, search queries may be another example type of command (e.g.,“what's the weather today?” or “where was David Bowie born?”). When theNMD determines that a voice input includes a search query, the NMD mayidentify a particular voice service (e.g., “GOOGLE”) to process thatvoice inputs that includes the search.

In some cases, the NMD may determine that the voice input includes avoice command that is directed to a particular type of device. In suchcases, the NMD may identify a particular voice service that isconfigured to process voice inputs directed to that type of device toprocess the voice input. For example, the NMD may determine that a givenvoice input is directed to one or more wireless illumination devices(e.g., that “Turn on the lights in here” is directed to the “smart”lightbulbs in the same room as the NMD) and identify, as the voiceservice to process the voice input, a particular voice service that isconfigured to process voice inputs directed to wireless illuminationdevices. As another example, the NMD may determine that a given voiceinput is directed to a playback device and identify, as the voiceservice to process the voice input, a particular voice service that isconfigured to process voice inputs directed to playback devices.

Within examples, the NMD may identify the particular voice service toprocess the voice input based on a previous input. A user might expectthat if a first voice input was processing by a given voice service,then a second subsequent voice input will also be processed by thatvoice service if the second voice input is directed to the same device,of the same type, or provided shortly after the first command, amongother possible contextual factors. For instance, the NMD may determinethat a previous voice input was processed by a given voice service andthat the present voice input is directed to the same type of operationas the previous voice input (e.g., both are media playback commands). Insuch a situation, the NMD may identify that voice service to process thepresent voice input.

As another example, the NMD may determine that a previous voice inputwas processed by a given voice service and that the present voice inputwas received within a threshold period of time after the previous voiceinput was received (e.g., within 1-2 minutes). To illustrate, playbackdevice 114 may receive a first voice input (“Hey Kitchen, play JanisJoplin”) and identify a voice service to process that first voice input,which my result in playback device 114 playing an audio track by JanisJoplin. Later, playback device 114 may receive a second subsequent voiceinput (“Turn it up”) and identify a voice service to process that secondvoice input. Given the similarity between the type of commands as mediaplayback commands and/or the duration between the two voice inputs,playback device 114 may identify the same voice service to process thesecond voice input as identified to process the first voice input.

In some cases, the NMD may identify a first voice service to process thevoice input, but then determine that the first voice service isunavailable to process the voice input (perhaps by failing to receiveresults within a certain period of time). A voice service may becomeunavailable for any number of reasons, such as an expired subscriptionto the service, a technical issue with the cloud service, or a maliciousevent affecting availability (e.g., a distributed denial-of-serviceattack).

In such cases, the NMD may identify a second, alternative voice serviceto process the voice input. The alternate might be a default voiceservice. Alternatively, multiple voice services registered to a systemmay be ranked by priority, and the alternative voice service may be thevoice service having the next highest priority. Other examples arepossible as well.

In some cases, the NMD may seek input from the user in identifying analternative voice service. For instance, the NMD may request that theuser provide an alternative voice service (e.g., “GOOGLE® is notcurrently responding, would you like to query an another service?”). Yetfurther, the NMD may identify an alternative voice service and confirmthat the user would like to query this alternative voice service instead(e.g., “SIRI® is not currently responding, would you like to queryALEXA® instead?”). Or, as another example, the NMD may query thealternative voice service and notify the user when returning the results(e.g., “CORTANA® was unavailable, the following results are fromSIRI®”). Once the original voice service becomes available, the NMD mayinform the user of this change in status and perhaps change the currentvoice service (e.g., “SIRI® is available now, would you like to querySIRI® instead?”). Such responses may be generated from stored audio dataon a data storage of the NMD, or that the NMD can access.

Where a second, alternative voice service is queried, the NMD mayattempt to apply one or more settings of the first voice service to thesecond voice service. For instance, if the query is to play back mediacontent from a particular artist and a default audio service isconfigured for the first voice service (e.g., a particular streamingmedia service), the NMD may attempt to query the second voice servicefor audio tracks by the particular artist from the default audioservice. However, if a different setting (e.g., a different defaultservice) is configured for the second voice service, such a setting mayoverride the setting for the first voice service when querying thesecond voice service.

In some instances, only a single voice service is available to the NMD.For instance, during set-up of a media playback system, a particularvoice service may have been selected for the media playback system. Insome cases, if a particular voice service is selected, wake-wordscorresponding to other voice services may be inactive such thatdetecting these wake-words does not trigger processing. A voice servicemay include various settings to modify behavior of the voice servicewhen queried with a voice input. For instance, a preferred or defaultstreaming media service may be configured. Media playback voice commands(e.g., “Play Katy Perry”) will source media content from that particularmusic service (e.g., audio tracks by Katy Perry).

c. Cause Identified Voice Service(s) to Process the Voice Input

At block 706, implementation 700 involves causing the identified voiceservice(s) to process the voice input. For instance, the NMD maytransmit, via a network interface to one or more servers of theidentified voice service(s), data representing the voice input and acommand or query to process the data presenting the voice input. Thecommand or query may cause the identified voice service(s) to processthe voice command. The command or query may vary according to theidentified voice service so as to conform the command or query to theidentified voice service (e.g., to an API of the voice service).

As noted above, the voice data may indicate a voice input, which may inturn include a first portion representing a wake-word and a secondportion representing a voice command. In some cases, the NMD maytransmit only the data representing at least the second portion of thevoice input (e.g., the portion representing the voice command). Byexcluding the first portion, the NMD may reduce bandwidth needed totransmit the command and avoid possible misprocessing of the voice inputdue to the wake-word, among other possible benefits. Alternatively, theNMD may transmit data representing both portions of the voice input, orsome other portion of the voice data.

After causing the identified voice service to process the voice input,the NMD may receive results of the processing. For instance, if thevoice input represented a search query, the NMD may receive searchresults. As another example, if the voice input represented a command toa device (e.g., a media playback command to a playback device), the NMDmay receive the command and perhaps additional data associated with thecommand (e.g., a source of media associated with the command). The NMDmay output these results as appropriate to the type of command and thereceived results.

Alternatively, if the voice command was directed to another device otherthan the NMD, the results might be directed to that device rather thanto the NMD. For instance, referring to FIG. 1, playback device 114 inthe Kitchen zone may receive a voice input that was directed to playbackdevice 112 of the Dining Room zone (e.g., to adjust media playback byplayback device 112). In such an embodiment, although playback device114 facilitates processing of the voice input, the results of theprocessing (e.g., a command to adjust media playback may be sent toplayback device 112). Alternatively, the voice service may send theresults to playback device 114, which may relay the command to playbackdevice 112 or otherwise cause playback device 112 to carry out thecommand.

While the NMD may cause the identified voice service to process somevoice inputs, other voice inputs may be processed by the NMD itself. Forinstance, where the NMD is a playback device, control device, or otherdevice of a media playback system, the NMD may include voice recognitionof media playback commands. As another example, the NMD may process thewake-word portion of a voice input. In some instances, processing by theNMD may provide a faster response time than processing using a voiceservice. However, in some cases, processing using a voice service mightprovide better results and/or results not available when processing viathe NMD. In some implementations, a voice service associated with theNMD (e.g. operated by the manufacturer of the NMD) may facilitate suchvoice recognition.

IV. Example Systems and Methods to Invoke Voice Service

As discussed above, in some examples, a computing device may use a voiceservice to process a voice command. Implementation 800 is an exampletechnique to cause a voice service to process a voice input.

a. Receive Voice Data Indicating a Voice Input

At block 802, implementation 800 involves receiving voice dataindicating a voice input. For instance, a NMD may receive, via amicrophone, voice data indicating a voice input using any of the exampletechniques described above in connection with block 702 ofimplementation 700, among other possible implementations.

b. Determine that the Received Voice Data Includes a PortionRepresenting a Generic Wake-Word

At block 804, implementation 800 involves determining that the receivedvoice data includes a portion representing a generic wake-word. Ageneric wake word might not correspond to a specific voice service.Instead, a generic wake-word may correspond to a NMD or media playbacksystem generally (e.g., “Hey, Sonos” for a SONOS® media playback systemor “Hey, Kitchen” for the Kitchen zone of a media playback system).Being generic, the generic wake word may be assumed not to invoke aparticular voice service. Rather, if multiple voice services areregistered, then the generic wake-word may be assumed to invoke all ofthe voice services to obtain the best results. Alternatively, if asingle voice service is registered, then the generic wake-word may beassumed to invoke that voice service.

c. Cause Voice Service(s) to Process the Voice Input

At block 806, implementation 800 involves causing one or more voiceservice(s) to process the voice input. For instance, a NMD may causevoice service(s) to process the voice input using any of the exampletechniques described above in connection with block 706 ofimplementation 700, among other possible implementations.

In some cases, multiple voice services are available to the NMD. Forinstance, multiple voice services are registered with a media playbacksystem that is associated with the NMD. In such examples, the NMD maycause each of the available voice services to process the voice input.For instance, the NMD may transmit, via a network interface torespective servers of the multiple voice service(s), data representingthe voice input and a command or query to process the data presentingthe voice input. The command or query may cause the identified voiceservice(s) to process the voice command. The command or query may varyaccording to each voice service so as to conform the command or query tothat voice service (e.g., to an API of the voice service).

After causing the voice service(s) to process the voice input, the NMDmay receive results of the processing. For instance, if the voice inputrepresented a search query or a media playback command, the NMD mayreceive search results or a command, respectively. The NMD may receiveresults from each voice service or a subset of the voice services. Somevoice services might not return results for every possible input.

d. Output Results from a Particular Voice Service of the VoiceService(s)

At block 806, implementation 800 involves outputting results from aparticular voice service of the voice service(s). If only results fromone voice services are received, the NMD may output those results.However, if results from multiple voice services are received, the NMDmay select particular results from among the respective results from themultiple voice services and output those results.

To illustrate, in one example, a NMD may receive a voice input of “HeyKitchen, play Taylor Swift.” The NMD may determine that the wake-wordportion of the voice input (“Hey, Kitchen”) is generic in that it doesnot indicate a particular voice service. Given this type of wake-word,the NMD may cause multiple voice services to process the voice input.However, if the wake-word portion of the voice input included a wakeword corresponding to a particular voice service (e.g., “Hey, Siri”),the NMD might instead cause only the corresponding voice service toprocess the voice input.

After causing the multiple voice services to process the voice input,the NMD may receive respective results from the multiple voice services.For instance, with the voice command “play Taylor Swift,” the NMD mayreceive Taylor Swift audio tracks from a first voice service (e.g.,ALEXA®) and search results related to Taylor Swift from a second voiceservice (e.g., GOOGLE®). Since the command was to “play” Taylor Swift,the NMD may select the audio tracks from the first voice service overthe search results from the second voice service. The NMD may outputthese results by causing the Kitchen zone to start playing the audiotracks.

In another example, the voice services included in the processing mightbe specific to a particular type of command. For instance, a streamingmedia service (e.g., SPOTIFY®) might have a voice service component foraudio playback related commands. In an example, a NMD may receive avoice input of “what's the weather?.” For this input, the voice serviceof a streaming media service might not return useful results (e.g., anull or error results). The NMD might select results from another voiceservice.

V. Example Systems and Methods to Register Voice Services

As discussed above, in some examples, a computing device may registerone or more voice services to process a voice command. Implementation900 is an example technique to cause a NMD to register at least onevoice service.

a. Receive Input Data Indicating a Command to Register Voice Service(s)

At block 902, implementation 900 involves receiving input dataindicating a command to register one or more voice services on one ormore second devices. For instance, a first device (e.g., a NMD) mayreceive, via a user interface (e.g., a touchscreen), input dataindicating a command to register one or more voice services with a mediaplayback system that includes one or more playback devices. In oneexample, the NMD receives the input as part of a procedure to set-up themedia playback system using any of the example techniques describedabove in connection with block 702 of implementation 700, among otherpossible implementations.

b. Detect Voice Services that are Registered to NMD

At block 904, implementation 900 involves detecting one or more voiceservices that are registered to the first device (e.g., the NMD). Suchvoice services may include voice services that are installed on the NMDor that are native to the NMD (e.g., part of the operating system of theNMD).

For instance, a NMD that is a smartphone or tablet may have installedone or more applications (“apps”) that interface with voice services.The NMD may detect these applications using any suitable technique.Techniques may vary by manufacturer or operating system of the NMD. Inone example, the NMD may compare a list or database of installedapplications with a list of supported voice services to determine whichsupported voice services are installed on the NMD.

In other examples, a voice service may be native to the NMD. Forinstance, voice services from APPLE® and GOOGLE® may be integrated intoor pre-installed on devices running the iOS and Android operatingsystems respectively. Further, some customized distributions of theseoperating systems (e.g., FireOS® from AMAZON®) may include a nativevoice service (e.g., ALEXA®).

c. Cause Registration of Detected Voice Service(s) on Devices

At block 906, implementation 900 involves causing registration of atleast one of the detected voice services to be registered on the one ormore second devices. For instance, the NMD may cause at least one of thedetected voice services to be registered with a media playback systemthat includes one or more playback devices (e.g., media playback system100 of FIG. 1). Causing the a voice service to be registered may involvetransmitting, via a network interface, a message indicating credentialsfor that voice service to the media playback system (i.e., at least onedevice thereof). The message may also include a command, request, orother query to cause the media playback system to register with thevoice service using the credentials from the NMD. In such manner, auser's media playback system may have registered one or more of the samevoice services as registered on the user's NMD (e.g., smartphone)utilizing the same credentials as the user's NMD, which may hastenregistration. Other benefits are possible as well.

VI. Conclusion

The description above discloses, among other things, various examplesystems, methods, apparatus, and articles of manufacture including,among other components, firmware and/or software executed on hardware.It is understood that such examples are merely illustrative and shouldnot be considered as limiting. For example, it is contemplated that anyor all of the firmware, hardware, and/or software aspects or componentscan be embodied exclusively in hardware, exclusively in software,exclusively in firmware, or in any combination of hardware, software,and/or firmware. Accordingly, the examples provided are not the onlyway(s) to implement such systems, methods, apparatus, and/or articles ofmanufacture.

(Feature 1) A method comprising receiving, via a microphone, voice dataindicating a voice input; identifying, from among multiple voiceservices registered to a media playback system, a voice service toprocess the voice input; and causing, via a network interface, theidentified voice service to process the voice input.

(Feature 2) The method of claim 1, wherein identifying the voice serviceto process the voice input comprises determining that a portion of thereceived voice data represents a particular wake-word corresponding to aspecific voice service; and identifying, as the voice service to processthe voice input, the specific voice service that corresponds to theparticular wake-word, wherein each voice service of the multiple voiceservices registered to the media playback system corresponds to arespective wake-word.

(Feature 3) The method of claim 2, wherein determining that the portionof the received voice data represents the particular wake-wordcorresponding to the specific voice service comprises querying wake-worddetection algorithms corresponding to each voice service of the multiplevoice services with the received voice data and determining that awake-word detection algorithm of the specific voice service detectedthat the portion of the received voice data represents the particularwake-word corresponding to the specific voice service.

(Feature 4) The method of claim 1, wherein identifying the voice serviceto process the voice input comprises determining that the received voicedata excludes any wake-word corresponding to a given voice service ofthe multiple voice services registered to the media playback system andbased on the determination, identifying, as the voice service to processthe voice input, a default voice service of the multiple voice services.

(Feature 5) The method of claim 1, wherein identifying the voice serviceto process the voice input comprises determining that (i) a previousvoice input was processed by a particular voice service and (ii) thevoice input was received within a threshold period of time after theprevious voice input was received and based on the determination,identifying, as the voice service to process the voice input, theparticular voice service that processed the previous voice input.

(Feature 6) The method of claim 1, wherein identifying the voice serviceto process the voice input comprises determining that (i) a previousvoice input was processed by a particular voice service and (ii) thevoice input is directed to the same type of operation as the previousvoice input and based on the determination, identifying, as the voiceservice to process the voice input, the particular voice service thatprocessed the previous voice input.

(Feature 7) The method of claim 1, wherein identifying the voice serviceto process the voice input comprises determining that the voice inputincludes a media playback command and based on the determination,identifying, as the voice service to process the voice input, aparticular voice service that is configured to process media playbackcommands.

(Feature 8) The method of claim 1, wherein identifying the voice serviceto process the voice input comprises determining that the voice input isdirected to wireless illumination devices and based on thedetermination, identifying, as the voice service to process the voiceinput, a particular voice service that is configured to process voiceinputs directed to wireless illumination devices.

(Feature 9) The method of claim 1, wherein identifying the voice serviceto process the voice input comprises determining that a portion of thereceived voice data represents a generic wake-word that does notcorrespond to any particular voice service and based on thedetermination, identifying, as the voice service to process the voiceinput, a default voice service of the multiple voice services.

(Feature 10) The method of claim 1, wherein the media playback systemcomprises multiple zones, and wherein identifying the voice service toprocess the voice input comprises determining that the voice input wasdirected to a particular zone of the multiples zones and based on thedetermination, identifying, as the voice service to process the voiceinput, a particular voice service that is configured to process voiceinputs directed to the particular zone of the media playback system.

(Feature 11) The method of claim 1, wherein identifying the voiceservice to process the voice input comprises determining that a portionof the received voice data represents a particular wake-wordcorresponding to a first voice service, determining that the first voiceservice is currently unavailable to process the voice input, andidentifying, as the voice service to process the voice input, a secondvoice service that is different from the first voice service.

(Feature 12) The method of claim 1, wherein the voice input comprises afirst portion representing a wake-word and a second portion representinga voice command, and wherein causing the identified voice service toprocess the voice input comprises transmitting, via the networkinterface to one or more servers of the identified voice service, (i)data representing at least the second portion of the voice input and(ii) a command to process the data representing the voice command.

(Feature 13) A tangible, non-transitory computer-readable medium havingstored therein instructions executable by one or more processors tocause a device to perform the method of any of features 1-12.

(Feature 14) A device configured to perform the method of any offeatures 1-12.

(Feature 15) A media playback system configured to perform the method ofany of features 1-12.

Additionally, references herein to “embodiment” means that a particularfeature, structure, or characteristic described in connection with theembodiment can be included in at least one example embodiment of aninvention. The appearances of this phrase in various places in thespecification are not necessarily all referring to the same embodiment,nor are separate or alternative embodiments mutually exclusive of otherembodiments. As such, the embodiments described herein, explicitly andimplicitly understood by one skilled in the art, can be combined withother embodiments.

The specification is presented largely in terms of illustrativeenvironments, systems, procedures, steps, logic blocks, processing, andother symbolic representations that directly or indirectly resemble theoperations of data processing devices coupled to networks. These processdescriptions and representations are typically used by those skilled inthe art to most effectively convey the substance of their work to othersskilled in the art. Numerous specific details are set forth to provide athorough understanding of the present disclosure. However, it isunderstood to those skilled in the art that certain embodiments of thepresent disclosure can be practiced without certain, specific details.In other instances, well known methods, procedures, components, andcircuitry have not been described in detail to avoid unnecessarilyobscuring aspects of the embodiments. Accordingly, the scope of thepresent disclosure is defined by the appended claims rather than theforgoing description of embodiments.

When any of the appended claims are read to cover a purely softwareand/or firmware implementation, at least one of the elements in at leastone example is hereby expressly defined to include a tangible,non-transitory medium such as a memory, DVD, CD, Blu-ray, and so on,storing the software and/or firmware.

I claim:
 1. A playback device of a media playback system, the playbackdevice comprising: one or more microphones; a network interface; one ormore processors; and data storage having stored therein instructionsexecutable by the one or more processors to cause the playback device toperform functions comprising: capturing audio from the one or moremicrophones into one or more buffers as a sound data stream; monitoring,via a first wake word engine, the sound data stream from the one or moremicrophones for a wake word associated with a specific voice assistantservice; monitoring, via a second wake word engine, the sound datastream from the one or more microphones for a wake word associated withthe media playback system; generating a first wake-word eventcorresponding to a first voice input when the first wake-word enginedetects sound data matching the wake word associated with the specificvoice assistant service in a first portion of the sound data stream;based on generating the first wake-word event, sending sound datarepresenting the first voice input to the specific voice assistant forprocessing of the first voice input; generating a second wake-word eventcorresponding to a second voice input when the second wake-word enginedetects sound data matching the wake word associated with the mediaplayback system in a second portion of the sound data stream;determining that the second voice input includes sound data matching oneor more playback commands; and based on (i) generating the secondwake-word event and (ii) determining that the second voice inputincludes sound data matching one or more playback commands, sendingsound data representing the second voice input to a voice assistantassociated with the media playback system for processing of the secondvoice input.
 2. The playback device of claim 1, wherein sending thesound data representing the second voice input to the voice assistantassociated with the media playback system comprises streaming, via thenetwork interface, the sound data representing the second voice input toone or more remote servers associated with the media playback system. 3.The playback device of claim 1, wherein the functions further comprise:receiving, from the voice assistant associated with the media playbacksystem, at least one playback instruction corresponding to the one ormore playback commands; and performing the at least one playbackinstruction.
 4. The playback device of claim 3, wherein the voiceassistant associated with the media playback system identifies specificmedia content based on the second voice input, and wherein the at leastone playback instruction instructs the playback device to play back thespecific media content.
 5. The playback device of claim 1, wherein thefunctions further comprise: generating a third wake-word eventcorresponding to a third voice input when the second wake-word enginedetects sound data matching the wake word associated with the mediaplayback system in a third portion of the sound data stream; determiningthat the third voice input includes sound data matching a particularplayback command; and based on (i) generating the third wake-word eventand (ii) determining that the third voice input includes sound datamatching the particular playback command, performing the particularplayback command.
 6. The playback device of claim 1, wherein thefunctions further comprise: generating a third wake-word eventcorresponding to a third voice input when the second wake-word enginedetects sound data matching the wake word associated with the mediaplayback system in a third portion of the sound data stream; determiningthat the third voice input includes sound data matching one or moresmart home commands; and based on (i) generating the third wake-wordevent and (ii) determining that the third voice input includes sounddata matching one or more smart home commands, causing one or more smarthome devices to carry out at least one smart home instructioncorresponding to the one or more smart home commands.
 7. The playbackdevice of claim 6, wherein causing the one or more smart home devices tocarry out at least one smart home instruction corresponding to the oneor more smart home commands comprises: sending sound data representingthe third voice input to a voice assistant for processing of the thirdvoice input.
 8. A method to be performed by a playback device of a mediaplayback system, the method comprising: capturing audio from one or moremicrophones into one or more buffers as a sound data stream; monitoring,via a first wake word engine, the sound data stream from the one or moremicrophones for a wake word associated with a specific voice assistantservice; monitoring, via a second wake word engine, the sound datastream from the one or more microphones for a wake word associated withthe media playback system; generating a first wake-word eventcorresponding to a first voice input when the first wake-word enginedetects sound data matching the wake word associated with the specificvoice assistant service in a first portion of the sound data stream;based on generating the first wake-word event, sending sound datarepresenting the first voice input to the specific voice assistant forprocessing of the first voice input; generating a second wake-word eventcorresponding to a second voice input when the second wake-word enginedetects sound data matching the wake word associated with the mediaplayback system in a second portion of the sound data stream;determining that the second voice input includes sound data matching oneor more playback commands; and based on (i) generating the secondwake-word event and (ii) determining that the second voice inputincludes sound data matching one or more playback commands, sendingsound data representing the second voice input to a voice assistantassociated with the media playback system for processing of the secondvoice input.
 9. The method of claim 8, wherein sending the sound datarepresenting the second voice input to the voice assistant associatedwith the media playback system comprises streaming, via a networkinterface, the sound data representing the second voice input to one ormore remote servers associated with the media playback system.
 10. Themethod of claim 8, further comprising: receiving, from the voiceassistant associated with the media playback system, at least oneplayback instruction corresponding to the one or more playback commands;and performing the at least one playback instruction.
 11. The method ofclaim 10, wherein the voice assistant associated with the media playbacksystem identifies specific media content based on the second voiceinput, and wherein the at least one playback instruction instructs theplayback device to play back the specific media content.
 12. The methodof claim 8, further comprising: generating a third wake-word eventcorresponding to a third voice input when the second wake-word enginedetects sound data matching the wake word associated with the mediaplayback system in a third portion of the sound data stream; determiningthat the third voice input includes sound data matching a particularplayback command; and based on (i) generating the third wake-word eventand (ii) determining that the third voice input includes sound datamatching the particular playback command, performing the particularplayback command.
 13. The method of claim 8, further comprising:generating a third wake-word event corresponding to a third voice inputwhen the second wake-word engine detects sound data matching the wakeword associated with the media playback system in a third portion of thesound data stream; determining that the third voice input includes sounddata matching one or more smart home commands; and based on (i)generating the third wake-word event and (ii) determining that the thirdvoice input includes sound data matching one or more smart homecommands, causing one or more smart home devices to carry out at leastone smart home instruction corresponding to the one or more smart homecommands.
 14. The method of claim 13, wherein causing the one or moresmart home devices to carry out at least one smart home instructioncorresponding to the one or more smart home commands comprises: sendingsound data representing the third voice input to a voice assistant forprocessing of the third voice input.
 15. A non-transitorycomputer-readable medium having instructions stored thereon that areexecutable by one or more processors to cause a playback device toperform functions comprising: capturing audio from one or moremicrophones into one or more buffers as a sound data stream; monitoring,via a first wake word engine, the sound data stream from the one or moremicrophones for a wake word associated with a specific voice assistantservice; monitoring, via a second wake word engine, the sound datastream from the one or more microphones for a wake word associated witha media playback system, wherein the media playback system comprises theplayback device; generating a first wake-word event corresponding to afirst voice input when the first wake-word engine detects sound datamatching the wake word associated with the specific voice assistantservice in a first portion of the sound data stream; based on generatingthe first wake-word event, sending sound data representing the firstvoice input to the specific voice assistant for processing of the firstvoice input; generating a second wake-word event corresponding to asecond voice input when the second wake-word engine detects sound datamatching the wake word associated with the media playback system in asecond portion of the sound data stream; determining that the secondvoice input includes sound data matching one or more playback commands;and based on (i) generating the second wake-word event and (ii)determining that the second voice input includes sound data matching oneor more playback commands, sending sound data representing the secondvoice input to a voice assistant associated with the media playbacksystem for processing of the second voice input.
 16. The non-transitorycomputer-readable medium of claim 15, wherein sending the sound datarepresenting the second voice input to the voice assistant associatedwith the media playback system comprises streaming, via a networkinterface, the sound data representing the second voice input to one ormore remote servers associated with the media playback system.
 17. Thenon-transitory computer-readable medium of claim 15, wherein thefunctions further comprise: receiving, from the voice assistantassociated with the media playback system, at least one playbackinstruction corresponding to the one or more playback commands; andperforming the at least one playback instruction.
 18. The non-transitorycomputer-readable medium of claim 17, wherein the voice assistantassociated with the media playback system identifies specific mediacontent based on the second voice input, and wherein the at least oneplayback instruction instructs the playback device to play back thespecific media content.
 19. The non-transitory computer-readable mediumof claim 15, wherein the functions further comprise: generating a thirdwake-word event corresponding to a third voice input when the secondwake-word engine detects sound data matching the wake word associatedwith the media playback system in a third portion of the sound datastream; determining that the third voice input includes sound datamatching a particular playback command; and based on (i) generating thethird wake-word event and (ii) determining that the third voice inputincludes sound data matching the particular playback command, performingthe particular playback command.
 20. The non-transitorycomputer-readable medium of claim 15, wherein the functions furthercomprise: generating a third wake-word event corresponding to a thirdvoice input when the second wake-word engine detects sound data matchingthe wake word associated with the media playback system in a thirdportion of the sound data stream; determining that the third voice inputincludes sound data matching one or more smart home commands; and basedon (i) generating the third wake-word event and (ii) determining thatthe third voice input includes sound data matching one or more smarthome commands, causing one or more smart home devices to carry out atleast one smart home instruction corresponding to the one or more smarthome commands.
 21. The non-transitory computer-readable medium of claim20, wherein causing the one or more smart home devices to carry out atleast one smart home instruction corresponding to the one or more smarthome commands comprises: sending sound data representing the third voiceinput to a voice assistant for processing of the third voice input.